In an image forming system having an image forming apparatus for forming an image on a recording medium based on image data, and a finishing apparatus for applying a process of finishing to the recording medium with the image formed thereon, a plurality of finishing apparatuses are arranged in series on the image forming apparatus as the basic unit of the image forming system, in order to perform a finishing step having any one of punching, folding, stapling and book binding processes, or a combination of such processes, in some cases.
In such cases, control communication or data communication from the image forming apparatus to a finishing apparatus located in the end position is carried out via a communication control sections of the finishing apparatuses located in a series of finishing apparatuses. Data communication includes transmission/reception of a large volume of data needed for a change of the combination of the finishing apparatuses and updating of the program including revision of the operation program, in addition to the normal communication. Particularly in the communication for the aforementioned configuration, relaying is necessary and this takes a long processing time. Further, it has been difficult to adjust timing for receiving and sending the communication data according to the prior art.
Patent Document 1 discloses an image forming apparatus wherein a dedicated built communication device is used to transfer a control program to a plurality of extended peripheral devices. This art allows a substantial reduction in the time for updating the program in a digital copying machine equipped with various options.
[Patent Document 1] Japanese Laid-Open Patent Publication No. 2002-247252
The aforementioned art is effective when a plurality of peripheral devices is connected in one-to-one relationship. However, in the configuration wherein a plurality of finishing apparatuses are arranged in series on the rear stage of the image forming apparatus and the control signal is transmitted via the communication IC of each finishing apparatus, a delay is caused in signal transmission and a longer processing time is required. Thus, there has been a long felt need for a further development to solve such problems.